Boiler-furnace.



Patented June 10,1913.

3 SHERIFF-SHEET 1.

WITNESSES: mvmron CM fl i a LIZ/Ma W2. 61%%M gy l g M. W. SEWALL.

BOILER FURNACE.

APPLICATION nun MAY 27. 1912.

3 8HEET8-SHBIIT 2.

WITNESSES." INVENTO R Qw/W mam timid f4 (2. yz w g g Patented June 10, 1913.

M. W. SEWALL.

BOILER FURNACE.

APPLICATION FILED MAY 27, 1912.

1,064,175.- Patented June 10, 1913.

WITNESSES. l/V I/EN TOR UNITED STATES PATENT OFFICE.

MINOTT W. SEWALL, OF NEW YORK, N. Y., ASSIGNOR TO THE BABCOCK & WILCOX COMPANY, OF BAYONNENEW JERSEY, A CORPORATION OF NEW JERSEY.

BOILER-FURNACE.

To all whom it may concern Be it known that I, MiNo'r'r WV. SEWALL, a citizen of the United States, residing at New York city, borough of Manhattan, in the county of New York and State of New York, have invented certain new and useful Improvements in Boiler-Furnaces, of WlllCll the following is a specification.

In U. S. Patents Nos. 983,000 and 983,170 granted to me January 31, 1911, I have shown furnace constructions designed for the purpose of producing complete combustion and the elimination of smoke with soft coal as a fuel. Both these furnaces in actual service accomplish the purpose for which they were designed. In their use, as well as in the use of other fire brick furnaces, it has developed that when in operation with certain fuels, large amounts of dust are carried from the fuel bed and are deposited on the top 'of the bridge wall, and that the dust also adheres to the side walls and to the roe-f of the furnace. \Vherever these deposits occur with a fire of comparatively low temperature, the accretions are easily removed from the briclnvork. If, however, the temperature of the fire is such that the dust deposited on the brick surfaces becomes fused, it adheres strongly to those surfaces, and if the furnace be run continuously for a long time, the deposit clogs the passageways, and this necessitates the discontinuance of the use of the furnace until such a time as it may be cooled down so that a man can get in and mechanically clean the accretions from the walls. It is also found that in some cases this material collects on the walls at a low temperature, and when later a high temperature of the furnace is attained, the material melts and flows down the walls to. the surface of the grates and clogs the grates to such an extent that no air Will pass through, and in the case of a chain grate it may run down through the grate and cool'in the spaces between the links, thereby preventing the movement of the grate. v

On account of the above mentioned diliiculties, it becomes necessary in many power houses to put the boilers out of service as often as once in ten days or two weeks for the purpose of cleaning out the passage- Specification of Letters Patent.

I Application filed May 27, 1912.

Patented J une 10, 1913.

Serial No. 699,860.

ways. It has also developed that although this same deposit takes place on the boiler tubes, or any water cooled surfaces to some extent, it does not adhere in such quantitics, and does not fuse to the surfaces as with brick walls, so that it is possible to remove the material by the use of a bar when the boiler is in operation, and it is frequently the case that if the fire is reduced to a low temperature the contraction will cause the material to drop from the tubes without the use of a bar. This being the case, it will be seen that if a furnace can be so constructed as to present water surfaces and brick surfaces so arranged that the brick areas will be comparatively small and interspersed with areas of water surface, and if such construction will accomplish the purposes of the furnace, they will be desirable for the reason that they will permit the boiler to remain continuously in service for a much longer time than otherwise, and such continuity is desirable from all points of view.

The present invention is designed to overcome the difliculties which have presented themselves in the general form of boiler shown in my said Patent No. 983,000 when using certain fuels, and will be understood by reference to the accompanying drawings in which-- Figure 1 is a vertical longitudinal section;

Fig. 2, a composite vertical section on theplanes of the lines 22 and 3-3 of Fig. l, the section on the former plane being at the left, and the section on the latter plane at the right in Fig. 2; Fig. 3, a horizontal section on the plane of the line 4- 1 of Fig. 1; Fig. 4-, a section on the plane of the line 5 5 of Fig. 1; and Figs. 5, 6 and 7, detail views of a part of the wall showing a special brick used in its construction and the manner of inserting it in place.

Similar reference numerals indicate similar parts in the several views.

Referring to the drawings, the numeral 1 designates the boiler casing, in the upper part of which are located the steam and water drums 2, held by suspension strapsas shown in Fig. 2. The'heating surface is composed of a bank 3 of inclined tubes, the ends of the tubes being expanded into uptake and downtake headers 4 and 5 respectively. Transverse baflles 6 and 7 divide the space containing the bank of tubes into a plurality of passes beginning at the uptake end. Supported on the lowermost row of 'tubes is a battle 8 extending from the rear 12 expanded into water boxes 13 and 14 which boxes are connected to the boiler circulation through the pipes 15 and 15'. In,

- this standard form of boiler construction the gases, before coming into contact to a sub stantial extent with the water tubes, are carriedbelow the first and second passes toward the rear of the boiler and thence back to the first pass before entering upon their course across the uptake end of the bank of tubes. In such construction I am able,

with highly volatile grades of bituminous coal, to hold the flame substantially back from the first pass and still maintain the accustomed steaming capacity and efliciency of the boiler substantially without smoking and the nuisance incident thereto. With certain fuels however,an accumulation of dust occurs as above stated requiring certain modifications of the design which will nowbe described.

- The furnace is inclosed by sidewalls com posed of water tubes 16 extending from substantially the grate level to the roof tubes 12, and above said roof tubes to the bank of tubes 3, and from the front to the rear wall; intervening bricks 17 supported on said tubes, and an external casing of steel plates '18 between which plates and fire bricks there is interposed a layer of nonconducting material. are expanded into front manifolds 19' and rear manifolds 20. Each manifold 19' is connected to the steam drums by a pipe 21; and each manifold 20 is connected by a pipe 22 to a box 23, the latter being connected to the steam drums by nipples 24;" The front wall is divided into a lower and an upper section, the lower section consisting of a fire brick wall #27 extending from the ignition arch 10 to the roof 11. The upper section consists of special fire bricks 25 which bricks surround the vertical tubes 15 which connect the front box 13 with the uptake headers 4..

cal tubes being protected by the same form of brick used for the protection of tubes 15. This special form of brick, as shown in Figs.

The water tubes 16 5, 6 and 7 may be introduced on edge be tween two adjacent tubes and turned on their fiat sides. A continuous wall may thus be formed wherever an approximately vertical line of tubes exists.

At the rear of the traveling grate 9 is a water box 29, and extending along both side walls approximately at the grate level, are water boxes 30. A second cross box 31 is placed above the box 29, and these two boxes, with their connections, form the bridge wall of the furnace. The water supply for this box system is from the rear manifolds 20 through tubes 32, the forward ends of said tubes entering the underside of'box 29 near its ends. Box 31 receives its waterusupply from box 29 through nipples 33 near the center of said boxes. The side boxes 30 receive their supply from box 29 through nipples 34, and their water dis-charge is through two pipes 35 at their forward or elevated end, into box 13. Box 31 has its discharge through pipes 36 into the front manifolds 19, and also through pipes 37 and 38 into box 13.

Immediately to the rear of box 29, and extending toward the mud drum 28 I have introduced'a screen of water tubes 39. This screen extends across the furnace, the ends of the tubes 39 being expanded into manifolds 40 and 41, the latter being at a higher level than the former in rder to give an inclination to the tubes 39. The water supply to manifold 40 enters from one of the manifolds 20 through nipple 42 (see Fig. 3), the circulation passing through tubes 39 into manifold 41 and from the latter into box 31 through a nipple 43 (see Fig. 1). a

From the foregoing description it will be seen that the furnace of my Patent No. 983,000 above referred to, have been modifie d in the following particulars: (1) the brick brldge wall has been abandoned and replaced by a bridge .wall of water cooled surfaces; (2) the side walls are composed of water tubes with brick work intervening, the side tubes being placed both below and above the roof tubes 12; (3) the roof tubes have been exposed to the heat of the furnace; and (4) a screen of water tubes has been introduced behind the bridge wall which will largely prevent the reflection of the heat from the combustion chamber downward into the pit behind the bridge wall. I have practically eliminated all brick surfaces upon which dust may be deposited with detrimental effects, and have substituted therefor water cooled surfaces from which the dust, if any accumulates, may be readily re- .moved. I am aware that the influence of these water cooledsurfaces is detrimental to the highest furnace temperature. Partially 1n consequence of this the volume of the furnace has been increased so as to reduce the velocity of the gases, and so that the water cooled surfaces shall be smaller relatively to the furnace volume than otherwise, and so as to reduce as much as possible their detrimental effect on the furnace temperature.

For the purpose of passing the ash and fuel refuse overthe rear end of the grate 0, I provide a shield or stripper 44 extending, preferably from approximately the rear edge of the water box 29, or approximately the tangent point of the curve of the grate. It is, however, not absolutely essential that this shield should reach as high on the grate as above stated, as a partial protection of the grate may be secured by having the upper edge of the shield as low, or perhaps lower, than the center of the sprocket shaft, one purpose of the shield being to conduct the ash'and fuel refuse which pass under the bridge wall over the top of the shield away from the grate and thus to prevent hot or burning material being discharged under the grate.

For the purpose of effecting complete combustion of any unconsumed carbon which may be discharged over the rear of the grate, I provide an auxiliary furnace having a grate or floor 45, one of the side walls of this furnace chamber providing a convenient means to which the shield or stripper 44 may be secured, as shown in Fig. 1. The procliicts of combustion from this auxiliary furnace pass directly up between the tubes 39 and mingle with the products of combustion from the furnace proper. An ash receiver 46 will receive the ash from the auxiliary furnace, said receiver being made air'tight with a controllable air entrance 47. A receiver 48 below the traveling grate receives any fine coal that may leak through the grate. This means of disposing of the ash and fuel refuse prevents the heating of the rear of the traveling grate and thereby obviates the objections before noted.

Fig. 4: shows a section through the upper side wall of the boiler, this wall consisting of refractory tiles 49, non-conducting material 50 and steel plates 51. The tiles are held in place by metallic strips 52 secured by bolts passing through said strips and plates. These bolts carry the weight of the bricks to the steel plates 51 thus relieving the upper side tubes 53 of the boiler of the weight which might otherwise come upon them. When expansion takes place the bank of tubes moves down and therefore no detrimental result can occur from such expansion.

In my application Serial No. 699,861, filed May 27, 1912 I have described and claimed the special provisions made to permit relative movement between the upper and lower sections of the side walls of the setting.

lVhat I claim and desireto secure by Letters Patent of the United States, is

' l. A boiler furnace having water tubes in the side walls, front and rear manifolds into which said tubes are expanded, said manifolds being connected to the boiler circulation, a cross box at the rear of the grate, pipes connecting said rear manifolds with the cross box, and an outlet connection from the said box to the front manifolds.

2. A boiler furnace having inclined water tubes in the side walls and extending from the front to the rear wall and from approximately the grate surface upwardly, front and rear manifolds into which the side tubes are expanded, said manifolds being connected to the boiler circulation, a cross box at the rear of the grate, pipes connecting said cross box with said rear manifolds, and an outlet connection from said box to the front. manifolds.

. A boiler furnace having water tubes in the side walls, front and rear manifolds into which said tubes are expanded, said manifolds being connected to the boiler circulation, a cross box at the rear of the grate, pipes connecting said rear manifolds with the cross box, an outlet connection from the said box to the front manifolds, side boxes extending longitudinally of the furnace, each side box being connected to the cross box at one end and to an outlet connection with the boiler circulation at its other end.

4. A boiler furnace having water tubes in the side walls, front and rear manifolds into which said tubes are expanded, said manifolds being connected with the boiler drums, a cross box at the rear of the grate, pipes connecting the rear manifolds with said box, a second cross box nippled to said first named cross box, and pipes connecting the said second box with the front Inanifolds.

5. A boiler furnace having water tubes in the side Walls, front and rear manifolds into which said tubes are expanded, said manifolds being connected with the boiler drums, a cross box at the rear of the grate, pipes connecting the rear manifolds with said box, a second cross box nippled to said first named cross box, pipes connecting the said second box with the front manifolds, side boxes extending longitudinally of the furnace, each side box having an inlet connection with said first named cross box, and an outlet connection.

6. A boiler furnace having roof tubes extending from the front to the rear wall, water tubes in the side Walls both above and below said roof tubes, and inlet and outlet connections for said roof and side tubes with the boiler circulation.

7. A boiler furnace having roof tubes, front and rear boxes into which said tubes are expanded, water tubes in the side Walls both above and below said roof tubes, a

cross box at the rear of the grate, an inlet connection from the side tubes to said cross box, and an outlet connection from said cross box to said front box.

8. A boiler furnace having roof tubes, front and rear boxes into which said tubes are expanded, water tubes in the side walls, front and rear manifolds into which the side tubes are expanded, a cross box at the rear of the grate, pipes connecting the rear manifolds with said cross box, an outlet connection from the latter to said front box and connections from said front and rear boxes to the boiler circulation.

9. A boiler furnace having roof tubes, front and rear boxes into which said tubes are expanded, water tubes in the side walls, a cross box at the rear of the grate, an inlet connection from the side tubes to said cross box, sidewater boxes extending longitudinally to the furnace and connected at one end to said cross box and at the other end to said front box, and connections from said front and rear boxes to the boiler circula- 10. A boiler furnace having roof tubes, front and rear boxes into which said tubes are expanded, said boxes being connected to the boiler circulation, water tubes in the side walls above and below the roof tubes, front and rear manifolds into which the side tubes are expanded, a cross box at the rear of the grate, pipes connecting the rear manifolds with'sa d cross box, and outlet connections from sa1d cross box. v

11. A boiler furnace having roof tubes, front and rear boxes into which said tubes are expanded, said boxes being connected to the boiler circulation, water tubes in the side walls, front and rear manifolds into which sald tubes are expanded, said manifolds bemg connected with the boiler circulation, a cross box at the rear of the grate, pipes connecting the rear manifolds with said cross 700K, side water boxes extending longitudinally with the furnace at approximately the grate level, each side boxobeing connected tothe cross box at one end and to said front box at the other end, and an outlet connection from said cross box to the front manifolds and to said front box.

12. A boiler furnace having water tubes in the side walls, front and rear manifolds into which said tubes are expanded, said grate, an inlet connection from the rear in the side walls, front and rear manifolds into which said tubes are expanded, said manifolds being connected to the boiler circulation, a traveling grate, a cross box at the rear of the grate, side boxes extending longitudinally of the furnace at substantially the grate level and connected to said cross box, a series of roof tubes, front and rear boxes into which said tubes areexpanded, inlet connections from the rear manifolds to said cross box, outlet connections from said cross box to the front manifolds and to said front box, and outlet connections from the side boxes to said front box.

14. A boiler furnace having water tubes in the side walls, front and rear manifolds into which said tubes are expanded, said front manifolds being connected directly to the boilerdrums by outside tubes, a box nippled to the boiler drums, pipes connecting the rear manifolds with said box, a cross box at the rear of theyrate, pipes connecting the rear manifolds with said cross box, and outlet connections from said cross box to the front manifolds.

15. A boiler furnace having front and rear walls of vertical tubes connected with the boiler circulation, side walls having water tubes, front and rear manifolds into which the latter tubes are expanded, said manifolds being connected with the boiler circulation.

16. A boiler furnace having front and rear walls of vertical tubes, fire brick covering said tubes, side walls having exposed water tubes, and connections from said tubes with the boiler circulation.

17. A boiler furnace having a series of JOHN A. WQDIXON, E. P. TERRY. 

